Let's give it this: BlackBerry's new Passport makes a big impact when you first hold it, thanks to its unusual square shape, its heft and the physical keyboard aimed at keeping its legion of qwerty loyalists happy.

BlackBerry no longer discloses how large its installed base of smartphone users remains, but it's probably still in the tens of millions worldwide simply because many older users love having a familiar qwerty keyboard. BlackBerry's first touchscreen phone, the Z10, was introduced in January 2013 and didn't sell well for various reasons, but the absence of a physical keyboard was considered one major factor.

BlackBerry officials believe that young professionals also can also be lured to a qwerty device, even though they're the prime market for touchscreen smartphones. How likely is that to happen? After spending a few days putting Passport through its paces, I'd say the folks at BlackBerry have their work cut out for them.

Hardware highlights

Overall, the Passport feels unusually heavy at 6.9 oz., and its size and sharp corners take some getting used to.

At 5 in. long by 3.5 in. wide, the Passport's body is not as long as the new 6.2-in. iPhone 6 Plus, but the Passport is almost half an inch wider. It's also thicker, at 0.36 in., compared to the 0.28 in. of the Plus. The Plus is also nearly an ounce lighter than the Passport.

While the Passport's size and weight should seem manageable, it took me an unusually long time to figure out how to hold it properly to type with my two thumbs. When I first held the Passport in two hands to type with both thumbs on the keyboard, I didn't balance it properly and nearly dropped it. You need to have your fingers stretched pretty far up the backside of the phone to keep it from falling away as your thumbs hit the keys.

BlackBerry

The Passport's physical keyboard should please qwerty fans, but not everyone will make use of its responsive touch surface to navigate the screen.

Some people claim they like a qwerty keyboard to be able to type blind, which can be useful when typing under a table during a meeting or when crossing a street to avoid getting hitting by a car. Unfortunately, I have never gotten that good at thumb-typing -- surely one my life's greatest failings. I will have to trust that this Passport can work for the superior thumb-typists among us, while I continue to toil in the trenches holding the phone in my left hand and picking out characters with my right forefinger. (But the tortoise won. Just sayin'.)

Once you get used to balancing the device, the three rows of qwerty keys at the bottom of the phone's front side are easy to push and use. The touchpad technology atop the keys sounds exotic -- you can use the physical keys to swipe up and down to browse a website or to swipe left and right in an email to define text and edit it.

But really, the feature wasn't all that valuable, or at least not to me. The technology allowing it to happen is interesting, I admit, but that's about the end of it. BlackBerry says the purpose of the keyboard's responsive touch surface is to keep your fingers out of the way of what's on the display, but that problem has never bothered me, and it doesn't with the Passport's touchscreen either.

The three rows of physical keys only allow you to see letters, but the Passport lets you view a row of numbers and related characters in added virtual rows on the screen just above the keyboard. It's a little distracting at first, though some will surely find it useful.

Overall, the design of the unit is attractive, with my all-black model highlighted by a polished stainless steel edge wrapped around all four sides. The metal is not only decorative; it is part of a forged stainless steel plate that extends inside the phone to add strength. The steel adds a professional look and looks good set against the black keyboard and the black of the rear case.

BlackBerry's square smartphone was designed to mimic the shape of a travel passport.

While the shape is intended to be distinct -- it mimics the shape of a travel passport -- the phone's sharp corners felt almost treacherous; they're a clear departure from the round corners in the Samsung Galaxy and iPhone lines.

The Passport's display is remarkably clear at 453 pixels per inch with a perfectly square 1440 x 1440 pixel resolution. The LCD display is very readable -- maybe one of the best on the market -- even outside in sunlight.

With the square display, the width is 30% greater than a typical 5-in. display of a rectangular smartphone. That extra room allows a display of 60 characters across, which compares favorably to the 40 characters on most phones and is close to the 66 characters in standard printed documents.

The two cameras in the Passport are top rate, although I didn't do much experimenting with either. A 13-megapixel rear camera comes with image and video stabilization and 1080p HD video recording at up to 60 frames per second, putting it on par from a specs perspective with almost any rear camera on the market. The front camera is rated at 2 megapixels and also has video and image stabilization, with 720p HD video recording. Both cameras are far above the 8-megapixel rear and 1.2-megapixel front camera in the new iPhone 6 Plus.

Two other hardware items jump out: The processor is a 2.2GHz quad-core Snapdragon 801, which is BlackBerry's first use of quad-core technology. Whether opening apps, loading websites or playing video, the Passport's processor performance was remarkably nimble. There's also 3GB of RAM, and 32GB of flash storage that's hot-swappable with a microSD slot that allows adding another 128GB.

The other outstanding hardware feature is a battery rated at 3,450 mAh, which is almost 50% more than smartphone batteries from a year ago, and rates nearly 20% higher than the battery in the iPhone 6 Plus. While Passport's battery is admirably capacious, it irks me that BlackBerry has decided users won't be able to remove it. BlackBerry seems to be telling us: 'OK, you asked for a bigger battery and we gave you one, but don't expect to replace it.' BlackBerry markets the battery as supporting up to 30 hours of mixed use, but I was able to go up to 40 hours per charge when browsing, playing videos and reading messages and emails several hours each day.

BlackBerry also enhanced audio in incoming phone calls with the Passport, which supposedly will allow the earpiece volume to increase automatically when a Passport user is in a loud environment, when the person on the other end is speaking softly or even when the phone simply isn't pressed close to the ear. I tried to detect this improvement, but wouldn't say it was all that noticeable. Perhaps I should blame the cellular AT&T network, and not the phone.

The Passport also includes an NFC chip for mobile payments and file exchange, as well as support for Bluetooth 4.0 Low Energy, Wi-Fi Direct, Miracast, and 2.4GHz 802.11 b/g/n. Also supported is FD-LTE, allowing global roaming capabilities.